With increasing frequency, some or our Danawoods neighbors have been impacted by the cost and inconvenience of “slab leaks”. Now, of course, the slab itself isn’t leaking. But our homes have copper supply lines in, through, and under our concrete slabs. For example, three or four of our friends with Chelsea or Bridgeport floorplans have discovered leaks in pipes between their laundry rooms and lower level bath. And make a mental note: having a leak in a hot water pipe is a huge advantage in one respect. It’s much more difficult to detect water leaking from the cold water pipes…

What causes the pipes to leak? It has been suggested to us that one common occurrence is the corrosion that occurs in copper pipes when in contact with the steel reinforcing bar (“rebar”) in the concrete slab. Galvanic action is the technical term for this type of corrosion between dissimilar metals. Here’s another explanation and photos of pinhole leaks that occur in copper pipes (photo courtesy of the Curaflo website).

Need a plumber? If you have a neighbor who has experienced a slab leak, ask them if they would recommend their plumber. Or contact us via email, and we would be happy to recommend our plumber, Dave Ortiz, who is outstanding.

One important warning: your home is built on what is called a “post-tension” slab. What this means to you, in regards to the warm floor under your feet, is that you cannot simply start jack-hammering the slab to find the leaky pipe. Post-tension slabs have tendons that are under incredible force and which keep your slab from cracking. Cutting through one of these tendons is a REALLY bad thing. In fact, you’ll often find that some plumbers will not cut into a slab because of the liability and danger involved. There is excellent background information on wikipedia regarding post-tension slab construction.